Automatic clothes washing machine



April 24, 1962 .1. ROTHENBERGER 3,030,789

AUTOMATIC CLOTHES WASHING MACHINE Filed A ril 24, 1958 5 Sheets-Sheet 1 A a c 7 Fig.7 t

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INVENTOR.

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AUTOMATIC CLOTHES WASHING MACHINE Filed April 24, 1958 5 Sheets-Sheet 4 (5 -R -V N .2 C P 1 I INVENTOR. 919(05 )fQlh f/ diffiil? April 24, 1962 .1. ROTHENBERGER AUTOMATIC CLOTHES WASHING MACHINE 5 Sheets-Sheet 5 Filed April 24, 1958 Fig.

INVENTOR.

.7405 nm'm'M/PMA BY 2 United States Patent 3,030,789 AUTOMATI QLOTHES WASEWG MAtIHHilE Jakob Rothenberger, 49 Kronleinstrasse, Zurich, Switzerland Filed Apr. 24, 1958, Ser. No. 730,572 "Claims priority, application Switzerland Apr. 27, 1957 3 Claims. (Cl. 68-12) The present invention relates to apparatus for washing textile fabrics comprising an automatic washing machine of the type having an inner cylinder and an outer cylindrical casing.

The present application is a continuation-in-part of my copending patent application, Serial No. 691,664, filed Oct. 22, 1957, now abandoned.

It is the primary object of the present invention to provide a control system for an automatic washing machine which will substantially shorten the duration of the washing operation of a washing machine.

A further object of the invention is the provision of a control system for a washing machine allowing for a method of washing which while being highly economical with respect to the consumption of water, heating energy and detergent, will yet have a substantially improved cleaning effect so as to more efficiently wash the goods in question.

Another object of the present invention is to provide for a controlled variation of the dirt and detergent concentration in the sud during the washing period.

A further object of the present invention is the provision of a washing machine which is very simple in design yet effective and reliable in operation and which will require very little attention from the operator at the beginning or during the washing operation.

A further object of the present invention is to provide for means automatically controlling the draining of spent washing liquid and the supply of fresh washing liquid during the washing period.

Still another object of the present invention is the provision of means controlling the supply of fresh washing liquid either as a function of the duration of the Washing period or as a function of the temperature of the sud.

Still a further object of the present invention is to provide for the control of the volume and/or duration of the supply of fresh washing liquid during the washing period.

These and other objects of the invention will become better apparent from the following description, taken in connection with the accompanying drawings in which:

FIG. 1 shows the liquid level in the outer cylinder during the Wetting-, washingand r'msing process.

FIG. 2 shows the liquid throughflow in a washing machine and a washing process according to the present invention;

FIG. 3 shows a temperature diagram of the suds in conventional washing machines and washing processes with continuous fresh water supply;

FIG. 4 shows a temperature diagram analogous to that of FIG. 3 in a washing machine and washing process in accordance with the present invention;

FIG. 5 is a sectional view of a washing machine embodying the present invention;

FIG. 6 is a graph schematically representing the energization periods of the electromagnet of the fresh-water supply valve;

FIG. 7 shows a graph representing the power input for heating;

FIG. 8 is a diagrammatic view of a control cam operating contacts for the electrical control of a fresh liquid supply valve and of heating.

FIG. 9 is a circuit schematic electrical diagram of the 3,030,789 Patented Apr. 24, 1962 control system with a thermostat for the temperature controlled fresh-water supply;

FIG. 10 is a schematic representation of the time switch in an exploded perspective view, and

FIG. 11 is a modified embodiment of a control system with respect to FIG. 9.

The washing process according to this invention is subdivided into three cycles: wetting (A), washing (B), and rinsing (C) and is carried out as follows:

During the wetting cycle (soaking), which lasts between approximately one and ten minutes, the revolving cylinder is filled to the overflow level and the loose dirt removed by fresh water continuously supplied. The duration of this Wetting cycle is determined mainly by the degree of soiling of the goods to be washed. While fresh water is supplied in this cycle, no heating is effected. V

In the subsequent washing cycle, the fresh water supply is first stopped and the heating started at the same time. Heating may be effected by steam, electric power, gas or other sources of heat. After a predetermined period fresh water is supplied during a relatively brief period which is only a fraction of the washing cycle. Since the washing machine is filled with liquid to the level of the overflow, a quantity of this liquid corresponding to the amount of fresh water supplied will drain through the overflow. According to the type of goods to be washed and the degree of soiling thereof, further quantities of fresh water may be supplied at certain time intervals. These fresh-water supplies may occur either in regular or in irregular time intervals and the quantity of water supplied may hp identical or different each time. It is advantageous to time the fresh water supplies so as to occur in the second half of the washing cycle in which the temperature of the suds has already reached a certain level and a large portion of dirt has been dissolved for removal by liquid discharge through the overflow. It has been found favourable for at least one of the fresh-water supplies to occur within the temperature range of 50 and C. for goods to be boiled, of 40 and 60 C. for coloured goods, and of 30 and 40 C. for woolens and artificial fibres.

The duration of the washing cycle is determined by the degree of soiling of the goods to be washed, the available heating energy rating of the machine and the type of goods; on an average it is between approximately 10 and 30 minutes.

With the conventional method water is supplied continuously throughout the washing cycle. As will be seen from FIGS. 1 and 2 however, the present invention provides for a supply of water only during predetermined periods of the washing cycle. At the same time a control variable discharge of spent liquid is provided. In FIGS. 1 and 2 the time t is entered on the abscissa, and the water level H or water quantity per unit time (air) respectively, on the ordinate.

With constant heating output of the washing machine, this intermittent water supply and discharge causes the water and suds respectively in the revolving cylinder to display a substantially dificrent temperature curve from that of a conventional washing method. In FIG. 4 the temperature point reached by the suds immediately prior to the first fresh-water supply is entered at x The comparative temperature point x, of a conventional curve shown in FIG. 3 is substantially lower, which is explained by the continuous supply of cold water. Depending on the type of washing machine, the available energy rating and the like, these curves will differ. With conditions otherwise unchanged, temperature differences of x :x =1:2 were found in washing machines operated according to both processes. The temperature curve ac- 25 cording to FIG. 4 is most important, as stated before, for the efiicacity of the detergents employed. All detergents placed in the machine can develop their full eifect with this temperature curve before part of them are discharged, owing to the fresh water supply, as dirt-impregnated suds.

The Washing cycle is followed by the rinsing cycle C during which the heating is stopped and fresh water continuously supplied. The fresh water supplied will remove residues of suds from the goods washed, and the temperature will drop.

Optimum values in respect of detergents to be employed, fresh water and heat consumed, and cleanness of the clothes are obtained if its to /2 0.8. gallon fresh water per pound dry goods is supplied during the washing cycle, and 2 or 3 US. gallons fresh water during the rinsing cycle.

Modification of the above quantities of water would have the following effects:

(1) If the quantity of water supplied during the washing cycle is larger: removal of unused, active substances, reduction of sud concentration, increase of heat consumption;

(2) If the quantity of water supplied during the washing cycle is smaller: insufficient discharge of the spent liquid and the dissolved dirt, goods would not be clean enough;

-(3) If the quantity of water supplied during the rinsing cycle is larger: unnecessary excess consumption of water, unnecessary prolongation of the rinsing cycle (water supply is constant), increased damages on the goods;

(4) If the quantity of water supplied during the rinsing cycle is smaller: unsatisfactory rinsing, sud residues in the goods.

Referring now to FIG. 5, it will be seen that the washing machine according to the present invention comprises a hollow cylinder 2 rotating about shaft 1, into which the goods to be washed are placed after opening of a closure 3. A number of lifting ribs 4 arranged within cylinder 2 cause the clothes to be moved along with the rotation of the cylinder. The cylinder 2 is driven by an electric motor 5 arranged in the base of the washing machine, the drive being transmitted, via V-belt 6, to a driving pulley 7 which is rigidly connected with shaft 1. The addition of detergents is effected through an opening 8 provided in a stationary exterior cylinder 13 surrounding cylinder 2. A container 9 communicates with the 'mains (not shown) via a supply line 10. Arranged in this container 9 is a float 11 which controls the supply of water through a valve 19 depending on its position. This arrangement is designed to reduce pressure and to equalize the pressure of the fresh water supplied to the cylinder 13. The discharge opening of valve 19 is connected with line 12 which is opened and closed by the electromagnetically controlled valve 17. This line opens into the stationary exterior cylinder 13, the said cylinder being coaxial with the inner cylinder 2. Arranged at a certain vertical distance from the bottom of the cylinder 13 is an open overflow tube 14 so that the water level may not increase above level H as long as this overflow is maintained open. A further drain pipe 15 connected to cylinder 13 serves for draining the washing machine after operation, or before the closure 3 is to be opened. A time switch 16 is provided, which performs the electrical control of the machine. According to its setting it transmits the corresponding impulses for the control of the electromagnetic valve 17 and controls the power supplied to the electrical heating elements 18. This time switch will be described in greater detail in connection with FIGS. 6 to 11.

FIG. 6 is a diagrammatic view of the control operations of the time switch for the actuation of the valve 17 for the fresh-water supply, t being the time and I the power supplied to the coil of the electromagnet of the valve. At the beginning of the wetting cycle A, the electromagnet of valve 17 is energized and the valve opened so that fresh water can flow into the cylinder through line 12. At the start of the washing cycle B, the circuit 7 is broken and the supply of fresh water interrupted. In the second half of the washing cycle, three relatively short power supplies occur, which cause corresponding supplies of fresh water to be passed due to opening of valve 17. The duration and timing of the power supplies and, consequently, fresh-water supplies, are predetermined by the setting of the time switch. At the beginning of the rinsing cycle C, the electromagnet of the control valve 17 is again energized so that fresh water is again continuously supplied to the revolving cylinder.

FIG. 7 shows the control operations for the electric heating in a manner analogous to FIG. 6. The heating is always on when the power for the electromagnet of the control valve 17 is interrupted, i.e. when fresh water is not supplied. Thereby a low energy rating for the machine will be sufficient. However, in cases where more energy is available the heating may be maintained in operation also when this electromagnet is energized. A corresponding arrangement of the contacts in the time switch is illustrated in FIG. 8. The contact disc 20 is rotated by the clockwork (not shown) of the time switch. The contact springs 21 are actuated in accordance with the recesses provided in the contact disc which the tripping pin 22 associated with the center spring engages. One pair of contacts is always closed while the other is open. Only one contact disc is therefore required for the control of the fresh-water valve and the heating, both circuits being mutually interlocked.

It is also possible to provide an embodiment in which the valve 17 (FIG. 5) is actuated in such a manner that fresh-water supplies of adjustable length and number are provided through line 12. These fresh-water supplies are initiated by a thermostat when the suds have reached a predetermined temperature. This device renders it possible to provide a single fresh-water supply of adjustable duration subsequently to the predetermined sud temperature having been reached.

As the container 9 (FIG. 5) and the float valve 11 automatically keep the liquid quantity passed through line 12 constant per time unit, the duration of the opening of the fresh-water valve also directly controls the liquid quantity supplied to the cylinder 13. As may be seen from FiG. 10, which shows the timing device of the control system of FIG. 9, timing is performed by a synchronous motor SM which is started together with the motor 5 of the driving cylinder 2. FIG. 9 shows that the control comprises a main relay R which jointly actuates the operating contacts r r r 1' and an auxiliary relay V which jointly actuates the operating contact 'v and the break contact v The coil of the auxiliary relay V is arranged in series with a manually operated switch M. T designates a temperature controlled switch or thermostat arranged in the suds container outside cylinder 2, and Z designates a time switch of which an embodiment is shown in greater detail in FIG. 10. C designates an electromagnet of a clutch 52 forming part of the time switch (FIG. 10).

As will be seen from FIG. 9, electromagnet N operating the fresh-Water valve 17 is connected in series with switch r while the clutch 52 of the electromagnet C is arranged in series with switch r The hand switch M is connected in series with the auxiliary relay V and with the parallel connection of switches r and v Furthermore, the main relay R is connected in series with the parallel connection of pairs of series-connected switches T and v and r., and Z respectively. The four series connections are all connected to the voltage source P. The time switch according to FIG. 10 comprises a setting knob 30 with associated scale 31 on which respective durations of the fresh-water supplies are indicated, by way of example, in minutes. The knob 30 permits to adjust via a shaft 32 the angular position of a stop pin 33a secured to a control disc 33 connected to this shaft. Arranged coaxially with the shaft 32 is a shaft 54 carrying control disc 34 rigidly connected therewith. The

latter is provided with a radially projecting pin 35 arranged to co-operate with the stop pin 33a in corresponding angular locations thereof. Arranged adjacent the pin 35 is a recess 36 designed to co-operate with a tappet 37 of switch Z, which is provided on a contact strip 38. The strip 38 co-operates with a second contact strip 39 so that contact is made While the tappet 37 does not register with recess 36 in the control disc. A spiral spring 40 is connected with one end to shaft 54 carrying control disk 24 while its other end is secured to stationary pin 53 and tends to rotate disc 34- over shaft 54 in the direction of arrow 41. The control disc 34 is in rotary connection with the electromagnetic clutch 52 over shaft 5 On the other hand the clutch is connected to shaft 55 and continuously rotated in the direction of arrow 42 by the motor SM via the reduction gear G while the motor 5 is in operation.

The control system described operates as follows:

The desired duration of each of the fresh water supplies is set at setting knob 30 and the stop 233a thereby rotated into a corresponding angular position with respect to scale 31. The spring as maintains the pin 35 on the control disk 34 in engagement with the stop 330. In the open position of the selecting switch M the water supply for the duration set by knob 31 will be provided until the washing cycle of the machine is completed of which time the voltage source P is disconnected by means (not shown). Due to the angular position of disc 34 the time switch Z remains closed.

When the predetermined suds temperature has been reached owing to the heat supplied by the heating members 18 (FIG. 5), the temperature switch or thermostat T measuring the temperature of the sud closes. This energizes the main relay R so that the switches r r r and r are closed. The fresh-water valve 17 and the clutch 52. are thereby energized. This causes the freshwater valve to be opened and the shaft 54 to be connected to the motor SM over the clutch 521, shaft 54 being then rotated in the direction of arrow 42. Fresh water will then flow through line 12 into the cylinder 13 until the control disk 34 driven by shaft 54 has completed its rotation against the action of spring 40", i.e. when the contact tappet 37 registers with the recess 36. This causes the time switch Z to open so that the relay R is deenergized since the temperature switch T has also been opened in the meantime owing to the supply of cold water reducing the temperature of the sud. The switches r r are opened by relay R so that the fresh-Water valve -17 is closed; clutch 52 is disengaged and the spring 44) will rotate the control disc 34 with its pin 35 into engagement with the stop 33a so that the time switch will again be closed. The initial position set by knob 30 is thereby restored, and as soon as the temperature of the sud has again reached the setting value of switch T, the latter will again close and release a new fresh-water supply of the duration set at the knob 3i Naturally, setting of the temperature switch T may be adjusted in accordance with any desired temperature of the sud.

If only one single fresh-water supply is to be effected during the washing cycle, the selecting switch M is closed. In this case when the temperature switch T closes, the auxiliary relay V is energized by closing of switch r over relay R. Relay V will in turn close the switch v and open the switch v When the time switch Z is opened due to movement of control disc 34 the relay R releases and cannot be energized again since the auxiliary relay V maintains the switch v open over switch 11;.

A control device somewhat simplified as compared to that shown in FIGS. 9 and designed for a single freshwater supply in dependence on the suds temperature is shown in FIG. 11. Duration of the fresh water supply may be set by rotating knob 30 by way of example, six

minutes. Disk 34 is displaced by this rotary movement 7 so as to close the switch Z over tappet 37. Only when the contact of the thermostat T closes owing to the predetermined sud temperature being reached, the motor SM will be set into operation and simultaneously the relay R will be energized so as to close the contacts r and r operated thereby. This causes the electromagnet N of the liquid supply valve 17 to open and to remain open until the motor SM has returned the cam disk 34 to its initial position in which knob 3t} will be 'back in zero position.

As soon as cam 34 has reached the initial position, the switch Z opens and the relay R is deenergized, thus opening contacts r and 1-, Repeated closing of the temperature switch T will thus effect no further supply of fresh water.

It is to be noted that after the wetting cycle A is ended subsequent to which the fresh-Water supply is discontinued, the continuous movement of the inner and rotatable cylinder 2 will displace water through overflow pipe 14 so that the water level in the outer stationary cylinder or casing 13 will drop continuously (cf. FIG. 1) until fresh water is again supplied. As the overflow is continuously open, spent or soiled sud is continuously removed in small quantifies, which causes the concentration of dirt to be reduced since the dirt will accumulate largely at the top of the sud. By draining spent soiled sud, the detergent content of the sud decreases to a lesser degree than the dirt content in this sud. The fresh-water supplies result again in a rise of the level during the washing cycle B. It is to be noted that more suds are removed than fresh water is supplied during the washing cycle B.

It would also be possible to provide only one fresh water supply of comparatively longer duration, e.g. of one-half to about five-sixths of the washing cycle B, while the quantity of water supplied per time unit is correspondingly reduced. Also it is possible for this water supply to be passed through a dosage valve or storage container instead of the pressure-reducing container 9 and the line 12. This would enable the quantity of fresh water supplied during the washing cycle to be adjusted to the weight of the goods to be washed placed in the machine and the degree of soiling. Moreover it would also be possible to provide two fresh-water lines of which the larger one operates during the Wetting and rinsing cycles and the smaller one during the washing cycle. The displacement eifect of the rotating cylinder 2 so as to drain spent liquid, can be increased in any known manner, such as by providing for scoops or blades thereon.

It is further noted that tube 14 could be provided with an electromagnetically actuated valve, controlled by a cam of the time switch 16, to provide a liquid level which is at least at the beginning of the washing period above the normal wetting level H.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. In an automatic washing machine comprising a rotating and perforated cylinder, a stationary casing surrounding said rotat-ing cylinder, and means for supplying a liquid to said casing and including valve means; a control system comprising actuating means for said valve means, variable temperature switch means arranged in said casing and subjected to the temperature of said liquid and operatively connected to said actuating means, electromagnetic means connected to said temperature switch means, timer means including constant speed drive means arranged for actuation by said electromagnetic means, cam means operatively connected to said drive means to be rotated thereby upon actuation by said electromagnetic means upon closing of said temperature switch means, time switch means connected to said actuating means and cooperating with said cam means, said cam means being provided to open said time switch means after rotation thereof over a predetermined angular range, and means for predetermining said angular range to thereby determine the time between said actuation of said drive means and the opening of said time switch means by said cam means, whereby said actuating means will open said valve means when said temperature switch means is closed and will close said valve means when said time switch means is opened by said cam means.

2. In an automatic Washing machine having a rotating cylinder, a casing surrounding said cylinder, and means for supplying a liquid to said casing and including a control valve therefor; a control system comprising a source of electrical current, a temperature switch arranged in said casing and subjected to the temperature of said liquid when contained in said casing, said temperature switch being adapted to close when said liquid has reached a predetermined temperature, a time switch connecting said temperature switch with said source of electrical current, a relay connected to said temperature switch to be energized when said temperature switch and said time switch are closed, a first relay switch contact and a second relay switch contact operatively connected to said relay for actuation thereby, said first and second contacts being closed when said relay is energized, an electromagnet in operative connection with said control valve for opening the latter when energized by said electrical current source, said first contact connecting said electromagnet with said source, an electric constant speed drive motor, said second contact connecting said drive motor with said time switch, a reduction gear connected to said drive motor, a timer cam connected to said reduction gear for rotation thereby in one direction, connecting means intermediate said timer cam and said time switch, said timer cam being adapted to maintain said time switch in closed position over a predetermined angle of rotation and to open said time switch when rotation of said cam through said angle has been completed, and a setting knob operatively connected to said timer cam and for rotation of the latter over said predetermined angle of rotation in a direction opposite to that imparted to said timer cam by said drive motor over said reduction gear and for closing said time switch, whereby when said temperature of said liquid has reached a predetermined temperature said first and second contacts will be closed by said relay so that said valve will open to admit liquid to said casing and said motor will be operated to rotate said cam, said valve being closed and said liquid supply interrupted after a period of time determined by said rotation of said timer cam over said predetermined angle selected by an operator and set by said setting knob.

3. In an automatic washing machine having a rotating cylinder, a casing surrounding said cylinder, and means for supplying a liquid to said casing and including valve means therefor; a control system comprising electromagnetic means for operating said valve means, time switch means connected to said electromagnetic means, temperature switch means arranged in said casing and subjected to the temperature of said liquid, said temperature switch means being closed when said liquid has reached a predetermined temperature, said temperature switch means being connected to said electromagnetic means, relay means connected to said temperature switch means, timer means including constant speed drive means arranged for actuation by said temperature switch means, gear means connected to said drive means, electromagnetic clutch means connected to said gear means and actuated by said relay means, cam means operatively connected to said clutch means to be rotated thereby in one direction upon actuation of the latter by said relay means when said temperature switch means are closed, said time switch means cooperating with said cam means, said cam means being provided to open said time switch means after rotation thereof over a predetermined angular range by said drive means over said clutch means from a setting position to an initial position, spring means connected to said cam means to be tensioned by rotation of the latter in said one direction over said predetermined angular range and to return said cam means over said range in a direction of rotation opposite to that imparted thereto by said drive means into said setting position, and means for predetermining said angular range and said setting position to thereby determine the time between said actuation of said drive means and the opening of said valve means and the opening of said time switch means by said cam means; whereby said electromagnetic means will open said valve means when upon reaching of said predetermined temperature in said liquid, said temperature switch means is closed to permit admission of liquid through said valve means and will be closed when said time switch means is opened by said cam means and whereby upon subsequent closing of said temperature switch means further liquid will be admitted to said casing during repeated rotation of said cam means from said setting position to said initial position.

References Cited in the file of this patent UNITED STATES PATENTS 1,961,606 Ells June 5, 1934 2,296,258 Breckenridge Sept. 22, 1942 2,366,949 Woppman et a1. Jan. 9, 1945 2,516,327 Kuhn July 23, 1950 2,628,489 Branson Feb. 17, 1953 2,635,445 Smith Apr. 21, 1953 2,693,097 Chatelain Nov. 2, 1954 2,872,075 Steiner Feb. 3, 1959 

